Food Poisoning: This is the most likely diagnosis given the symptoms of abdominal pain, nausea, vomiting, and diarrhea following food consumption. Food poisoning can be caused by a variety of pathogens including bacteria (e.g., Salmonella, E. coli), viruses (e.g., Norovirus), and parasites, and its presentation matches the described symptoms closely.

Irritable Bowel Syndrome (IBS): Although IBS is a chronic condition, an acute exacerbation could be triggered by certain foods, leading to the described symptoms. IBS is characterized by recurrent abdominal pain associated with a change in bowel habits, which could include diarrhea.
Lactose Intolerance: This condition is caused by the inability to digest lactose, a sugar found in milk and other dairy products, due to a deficiency of the enzyme lactase. Symptoms include bloating, gas, diarrhea, and abdominal cramps after consuming lactose-containing foods.
Gastroesophageal Reflux Disease (GERD): While GERD primarily causes heartburn and regurgitation, some patients may experience nausea and vomiting, especially after eating trigger foods. However, diarrhea is less commonly associated with GERD.

Appendicitis: Although appendicitis typically presents with right lower quadrant abdominal pain, nausea, vomiting, and sometimes diarrhea, it is a surgical emergency that must not be missed. The initial presentation can be atypical, and food intake might exacerbate the pain.
Intestinal Obstruction: This is a condition where there is a blockage in the intestines that can cause severe abdominal pain, nausea, vomiting, and constipation or diarrhea, depending on the level of obstruction. It is a medical emergency.
Inflammatory Bowel Disease (IBD): Conditions like Crohn's disease and ulcerative colitis can present with abdominal pain, diarrhea, and sometimes nausea and vomiting. While not typically triggered by food in the same way as food poisoning, certain foods can exacerbate symptoms.

Celiac Disease: An autoimmune disorder where the ingestion of gluten leads to damage in the small intestine, causing abdominal pain, diarrhea, and sometimes nausea and vomiting. It's less common than other gastrointestinal issues but important to consider in patients with persistent symptoms.
Eosinophilic Gastroenteritis: A rare condition characterized by the presence of eosinophils in the gastrointestinal tract, which can cause abdominal pain, nausea, vomiting, and diarrhea. Food allergies or sensitivities might trigger symptoms.
Whipple's Disease: A rare, systemic bacterial infection (Tropheryma whipplei) that can cause malabsorption, weight loss, abdominal pain, and diarrhea. It's a diagnosis of exclusion and requires a high index of suspicion.